When it comes to interior house painting, one of the most common questions is “how much area will one gallon of paint cover?” The answer depends on several factors, including the type of paint, the surface being painted, and the application method. Keep reading to learn more about how to estimate paint coverage and how much area one gallon of paint will typically cover.
What Impacts Paint Coverage
There are several key factors that determine how many square feet a gallon of paint will cover:
- Type of paint – The thickness and opacity of the paint impacts coverage. For example, flat paint tends to cover more area than gloss paint.
- Paint quality – Higher quality paints usually provide better coverage. Budget paints may take more coats to achieve full coverage.
- Surface material – Rough or porous surfaces like stucco or concrete will require more paint than smooth drywall.
- Surface preparation – Properly prepping and priming the surface can improve paint coverage.
- Application method – Using rollers, brushes, or sprayers can affect how efficiently the paint covers an area.
- Number of coats – Additional coats will be needed to cover properly and provide full color saturation.
These factors should all be taken into consideration when estimating how far a gallon of paint will go for your particular painting project.
Typical Paint Coverage Rates
As a general rule of thumb, one gallon of interior latex wall paint will cover 350-400 square feet of properly prepared and primed drywall or plaster. Here are some more specific coverage estimates based on the type of paint and surface:
| Paint/Surface Type | Coverage Per Gallon |
|---|---|
| Flat latex paint on drywall | 400 sq ft |
| Eggshell latex paint on drywall | 400 sq ft |
| Satin or semi-gloss latex paint on drywall | 350-400 sq ft |
| High gloss latex paint on drywall | 300-350 sq ft |
| Primer on drywall | 300-400 sq ft |
| Flat or eggshell paint on plaster | 300-350 sq ft |
| Semi-gloss paint on plaster | 250-300 sq ft |
| Flat paint on wood | 350-400 sq ft |
| Gloss paint on wood | 300-350 sq ft |
| Primer on wood | 300-350 sq ft |
| Paint on stucco or concrete | 100-150 sq ft |
These coverage rates assume proper surface prep and application using brush, roller, or sprayer. Using a paint sprayer can improve coverage slightly compared to brushes or rollers.
Factors That Reduce Paint Coverage
While the above estimates provide a good general rule for expected coverage, certain factors can reduce the actual coverage rate of paint:
- Insufficient surface prep – Paint will soak into poorly prepared surfaces, requiring more paint.
- Dark or bold colors – Deep colors often require a primer coat and extra coats of paint to fully cover.
- Old worn surfaces – Previously painted surfaces in poor condition will soak up more paint.
- Porous surfaces – Plaster, concrete, wood and other porous surfaces may need 2-3 coats of paint.
- High contrast – When painting a dark color over a light color, extra coats are needed.
- Heavy application – Overloading paint on the surface can lead to excess waste.
To save on paint, properly prepare all surfaces by cleaning, repairing flaws, sanding and priming before painting. Also avoid applying the paint too heavily during each coat.
Tips for Maximizing Paint Coverage
Here are some useful tips to help maximize the coverage from each gallon of paint:
- Use quality applicator tools – Good quality brushes, rollers and spray equipment will help efficiently apply the paint.
- Follow the spread rate – Check the manufacturer’s recommended wet film thickness and spread rate per coat.
- Apply multiple thin coats – Using multiple thinner coats will often cover better than one thick coat.
- Maintain a wet edge – Keep a wet edge as you paint to avoid lap marks and uneven coverage.
- Use the proper primer – Primer improves topcoat coverage, so prime all surfaces appropriately before painting.
- Check paint expiration date – Old paint loses effectiveness and will not cover as well.
- Stir paint thoroughly – Stirring ensures even consistency and maximizes coverage.
Taking steps to use the paint as effectively as possible will increase the coverage rate and reduce overall paint usage. Wasting less paint can help save money on your painting projects.
Estimating How Much Paint is Needed
To estimate the amount of paint needed for a room, first measure the room’s wall space in square feet. Only include wall space that will be painted. Next, subtract the square footage of doors and windows. Finally, divide the total wall square footage by the paint’s coverage rate per gallon. This will tell you approximately how many gallons of paint to buy for the room.
For example, a room with four walls each 10 ft x 8 ft (80 sq ft per wall) has 320 sq ft of total wall space. Subtract 50 sq ft for a door and two windows. That leaves 270 sq ft of wall to be painted. Using a latex wall paint with a coverage rate of 350 sq ft per gallon, you would need:
- Total wall square footage = 270 sq ft
- Coverage per gallon = 350 sq ft
- Gallons needed = Total sq ft / Coverage per gallon
- 270 sq ft / 350 sq ft per gallon = 0.77 gallons
For the 270 sq ft room, you would need to purchase 1 gallon of paint. Always round up to the nearest whole gallon when estimating paint quantity needs.
Conclusion
Determining paint coverage rates can seem complicated, but the square footage a gallon of paint will cover depends largely on the paint and surface type. On average, one gallon of interior latex wall paint will cover 350-400 square feet of properly prepped and primed drywall or plaster. Factors like surface porosity, quality application tools, proper preparation, and application technique can all maximize paint coverage. Considering these key factors will help estimate how much paint you need to tackle any painting project.
